It is the objective of this project to determine if there is a defect in axonal dendritic flow (neuroplasmic flow) in cortical neurons of patients suffering from Alzheimer's disease - senile dementia. To this end neurons in experimental animals and in man will be studied in-vitro to determine normal patterns of movement of particles in axons and dendrites. Movements will be observed visually and by means of time lapse photography using Nomarski differential interference contrast microscopy on living tissue culture preparations of neurons in organized or dissociated cultures. As an adjunct to the study of normal particulate movements in nerve cell processes the effects on these movements caused by varying environmental temperatures, oxygen concentration, colchicine, vinblastine and other mitotic spindle inhibitors will be studied. By these means normal patterns of particulate movements in nerve cell processes will contrast with expected alterations in similar movements in the neurons from patients with Alzheimer's disease and senile dementia.